1. Field of the Invention
The present invention relates generally to magnetic sensors and specifically to magnetic sensors of the type wherein a magnetic transducer reads a ferromagnetic target configured in a unique pattern to yield information about a mechanical application.
2. Discussion of the Related Art
Many types of magnetic sensors are known in the art. Many of these use Hall effect or magnetoresistive (MR) transducers combined within a magnetic or ferromagnetic target having a pattern of features keyed to details within a mechanical apparatus being monitored by the magnetic sensor. These features may be the magnetic signature of a magnetized target or the presence or absence of ferromagnetic metal in various sizes on a metal target placed near the transducer. Exemplary of one such system is U.S. Pat. No.5,469,054 to Bicking.
When the metal target is circular in shape the sensing system is called a "gear tooth sensor" from the resemblance of the target to a toothed mechanical gear. These gear tooth sensors are often used in the automotive arts wherein the target is linked to crankshaft for use in engine control. Sensor designers continually seek refinement of the target system to improve engine control.